U.S. patent application Ser. Nos. 12/146,810 and 12/146,836 disclose systems and methods useful for creating unique optical signatures. In one described example, a unique optical signature can be created by an optical signature chamber containing a plurality of discrete, non-uniform, randomly disposed objects in relatively fixed but changeable positions with respect to each other that create a unique optical signature when light from a light source is directed through the optical signature chamber. In another described example, an optical signature chamber contains a fluid that creates an optical signature when light is directed through the optical signature chamber.
The unique optical signature can be used in any of a large number of applications including, but not limited to, the construction of an encryption key or uniquely identifying an object such as an electronic device.
In certain applications, particularly high security applications, it is important to prevent unauthorized access to the unique signature in order to prevent duplication or replication of the signature that can, for example, be used to gain unauthorized access to sensitive data or allow unauthorized use of equipment. In the case of current encryption technology, the encryption key is intended to be erased from memory if an unauthorized person tries to access the encryption key. However, this active erasure approach requires active power or a battery source, which is not necessarily always present. Additionally, the erasure timeline of an active erasure approach may be too long for some application environments.